Adhesion formation after peritoneal surgery is a major cause of postoperative bowel obstruction, in fertility, and chronic pelvic pain. In addition, adhesion formation can occur after abdominal, gynecological, cardiac, thoracic, spinal, ENT, or orthopedic (e.g. tendon, joint, and knee) surgery. Therefore, a methodology by which adhesion formulation after surgery could be reduced or prevented would be of great benefit in reducing postoperative morbidity.
The most straightforward approach to reducing the incidence of adhesion formation remains physically maintaining the adhesiogenic surfaces apart with a mechanical barrier. For example, U.S. Pat. No. 6,403,655, assigned to Ethicon, Inc., describes a method of preventing adhesion formation between tissues by placing a polyoxaester adhesion prevention barrier between such tissues. Exemplified in the disclosure are a polyoxaester of 3,6-dioxaoctanedioic acid and ethylene glycol, as well as a copolymer of polyoxaester/caprolactone/glycolide.
U.S. Pat. No. 5,644,002, also assigned to Ethicon, Inc., describes absorbable polymers and blends of polycondensation polyester and aliphatic polyesters based on lactone monomers, where the polycondensation polyester is the reaction product of diglycolic acid and an alcohol selected from selected from the group consisting of glycerol, pentaerythitol, trimethylolpropane, hydroxyl terminated poly(ethylene glycol)s, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butylene glycol, dipropylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-octanediol. This reference teaches that the incorporation of hydroxyl terminated poly(ethylene glycol)s in the polycondensation polyester is desirable because it leads to polymers which are useful as adhesion prevention barriers. Additionally, this reference discloses that ultrathin coatings of about 1 to about 1000 microns can be applied to tissue surfaces for the prevention of adhesions.
U.S. Pat. Nos. 3,997,512, 4,048,256, 4,076,798, 4,095,600, 4,118,470, and 4,122,129, assigned to American Cyanamid Company, describe biocompatible and absorbable polycondensation polyesters, which are the polycondensation product of diglycolic acid and glycols such as ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and the like. Specifically, U.S. Pat. No. 4,095,600 describes a reaction product of (a) about 2 to 50% by weight of the polycondensation polyester and (b) polyglycolic acid, based on the total weight of the polycondensation polyester and polyglycolic acid, to form a self-supporting polymeric film for use, for example, in drug delivery. This reference is silent with respect to use of the composition for adhesion prevention.